Fig. 8: PD-L2 expression correlates with host age in murine and human melanoma, including in distinct intratumoural myeloid cell subsets.

a–c Data from mouse B16 scRNA-seq dataset accessed from the Broad Institute scRNA database repository SCP1261. a UMAP overlay displaying cell type annotation in murine B16 melanoma dataset. b Stratification of UMAP plot by host age. c PDCD1LG2 (PD-L2) gene expression stratified by host age and cell type. d–h Data from three pooled human melanoma scRNA-seq datasets (GSE120575 n = 32 human donors, GSE72056 n = 19 human donors, GSE115978 n = 16 human donors). d UMAP overlay displaying cell type annotation. e Subclustering of myeloid cell types including monocytes (Mono), conventional type 1 dendritic cells (cDC1), conventional type 2 dendritic cells (cDC2), plasmacytoid dendritic cells (pDC), migratory dendritic cells (migDCs), PLA2G7 high interstitial macrophages (PLA2G7.IMs), RNASE1 high interstitial macrophages (RNASE1.IMs), and cycling myeloid cells (Cycling). f Gene expression of markers defining clusters identified in e. g PDCD1LG2 gene expression stratified by cell types and host age (median host age 67 years). h Statistical analysis of PDCD1LG2 gene expression in myeloid subclusters identified in e stratified by host age > or <73. i Linear correlation plots of PD-L2⁺ immune cell subsets versus age in cancer patients versus healthy donors (tumour infiltrating [n = 10 human donors]; peripheral blood [healthy donor n = 3 human donors]; [cancer patient n = 10 human donors]). Standard error of mean indicated; p-values (i) linear regression (h) unpaired Student’s t-test (*, p < 0.05, ****, p < 0.0001).